The Strategic Costs of the Weakened US-ROK Exercises

A live firing drill during joint exercises between the US and ROK in April 2017 in Pocheon, South Korea. Photo Credit: AFP.

In response to an increasingly hostile China, Washington has devised a strategy designed to leverage its existing alliance system in Asia, including its partnership with South Korea, to augment its power. The US-ROK alliance offers a powerful framework for collective action, but incumbent leadership in South Korea appears hesitant to fully support this strategy, mainly due to China’s powerful influence over Seoul. Among the public, there has also been a fierce debate over the choice between the U.S. and China.[i] Given this political landscape in South Korea, Washington should pursue efforts designed to win over the Korean public to America’s side. A decision by President Donald Trump to permanently scale down the US-ROK combined military exercises, however, could make this challenge harder; it would reduce the US ability to exploit these exercises to shape public perception in South Korea and generate goodwill for United States. Unfortunately, this seems to be the path that the Trump administration is going. But it is not too late to alter course. Washington should recommit to more extensive exercises and other trust-building measures with the ROK over the coming years and, through these efforts, win over skeptical members of the South Korean public.

Strategic Problems with the Low-key Exercises

During the 2018 Singapore Summit, President Trump hammered out a diplomatic deal with his North Korean counterpart, Kim Jong Un, that sought to contribute to the end of the 70-year-long enmity between their two countries. One of the US commitments was to scale down its combined military exercises with South Korea. Shortly after the summit, Washington and Seoul cancelled the 2018 Ulchi-Freedom Guardian (UFG) exercise, which was then fully terminated in 2019. The two allies also downsized their major springtime exercise, Key Resolve-Foal Eagle (KR/FE), to the level that, according to then-Secretary of Defense Jim Mattis, “[would] not be harmful to diplomacy.”[ii] The ostensible rationale for these truncated exercises is to appease Pyongyang, yet Trump’s vitriolic tirades against these military maneuvers and their financial cost imply that his real motives are somewhat different. Thus, it seems that the current administration is unlikely to restore the scale of the US-ROK exercises back to previous levels even if diplomacy fails to bear fruit.

Given this grim outlook, there exist legitimate risks to the US-ROK combined forces’ existing operational capabilities, particularly as they relate to interoperability and combined operations.[iii] Yet an even bigger problem for the U.S. is unfolding at the strategic level. In response to China’s growing influence in Asia, Washington has laid out the Free-and-Open Indo Pacific (FOIP) Strategy organized around its existing alliance system in Asia.[iv] President Trump has struggled to incorporate the US-ROK alliance into the framework of the Strategy, however, because President Moon Jae-in—fearing the potential reaction from a Beijing concerned about American containment and willing to flex its economic might against South Korea—has been extremely reticent to fully join these US efforts.[v] Given this cautious approach, achieving Washington’s strategic objectives with South Korea will require a profound and durable base of support within the Korean public.

The massive combined military exercises have contributed to the maintenance of public support over the past decades. Indeed, the deployment of costly US strategic assets in support of the exercises helps Washington enhance its credibility as a security guarantor. In addition, the exercises provide South Korean participants with firsthand experience and knowledge that allow them to better conceptualize how the US-ROK alliance would operate in the event of war. If reductions in the scale and scope of the exercises continues, though, the current base of support for the alliance within South Korea may fray. To make matters worse, the growing power of millennials in South Korean politics is likely to further undermine the foundation of existing support for the United States as a whole. Consequently, the Trump administration may find itself facing enduring challenges if it seeks to enlist South Korean support for its response to collectively balancing a rising China.

Shaping Perceptions through the US-ROK Combined Exercise

Before the aforementioned reductions, the US-ROK combined exercises mobilized a massive number of personnel both from within and outside the Korean Peninsula. According to the Department of Defense, the 2017 UFG exercise mobilized approximately 17,500 US troops, including 3,000 not based on the peninsula.[vi] Washington has also occasionally included several strategic assets in the force package whose purpose is to signal Pyongyang that the U.S. is firmly committed to defending Seoul. This signal was so strong during the 2017 UFG exercise that even China voiced concern regarding the presence of so many powerful American assets in the region. The core of this show of force was the deployment of the USS Carl Vinson (CVN-70) and the USS Ronald Reagan (CVN-76) battle groups, which conducted dual-carrier training during the exercise.[vii]

But while these ostentatious displays reassure allies and signal resolve to potential adversaries, the deployment of aircraft carriers and strategic bombers have also imposed very real financial costs on the U.S. This costly signal of support is frequently highlighted by South Korean media, which uses its platform to remind the public about the significance of these costly deployments.[viii] Thus, these expensive performances aren’t for nothing: they allow the U.S. to send a signal to the South Korean public that the U.S. is willing to pay enormous military costs to fulfill its security commitments,[ix] and they reassure the Korean public that the U.S. is capable of projecting its mighty forces quickly enough to defeat any aggression by the North.[x] One recent and noteworthy example of the media power of these displays occurred during the 2017 KR/FE exercise when a report about the participation of the US Navy SEAL Team Six, one of the most elite special operations forces in the world, excited both the South Korean media and public.[xi]

Exercises also influences South Korean perceptions by allowing people-to-people contacts. In every exercise, Seoul has mobilized a substantial number of its personnel across the nation. For example, the ROK mobilized more than 300,000 soldiers and government officials for the 2018 KR/FE exercise.[xii] Thus, the exercises provided a large cadre of South Koreans with an opportunity to mingle with their US counterparts, observe American capabilities and practices, and learn how the US-ROK alliance would operate in the event of an attack against their nation. Moreover, basic principles of social psychology suggest that even the mere exposure to US troops might produce feelings of kinship among Koreans, which would be reciprocated by American forces, resulting in a strong in-group identity.[xiii]

What makes this dynamic particularly potent is its potential to spill over into broader South Korean civil society. Among Korean troops who have participated in every combined exercise, 70% were male conscripts from ages 18 to 26 who are required to serve in the ROK armed forces.[xiv] Because these conscripts almost all return to civilian life after serving their mandatory time in the armed forces, the views and opinions of the U.S. formed during US-ROK exercises are not just limited to the military realm – they constantly circulate into wider civil society, contributing to a strong sense of shared understanding and respect.

And this phenomenon is evident in the data. In a survey asking South Korean males if US unilateralism is a threat to South Korea’s interests, 92.86% of respondents aged 20 or younger thought American unilateralism threatened South Korea. However, this number appears greatly reduced for those aged 21-24 and 25-28—the age brackets containing those that have completed their mandatory military service—to 58.33% and 48.78% respectively.[xv] With this result, one scholar suggests that “[t]his fits perfectly with the high degree of cooperation between the South Korean military and the U.S. military, as well as the widely held notion that the U.S. serves as a deterrent against North Korean invasion.”[xvi] Thus, once they are released back to a civilian life after their two years of service, their knowledge and perceptions, shaped in favor of the United States, could help these reservists defend the US-ROK alliance against possible opposition raised by fellow citizens with no military experience, thereby buttressing the public’s support for the United States.

But Washington and Seoul have downsized these beneficial exercises and refrained from advertising them. If this trend continues, the South Korean public may raise questions about the value of spending taxpayer money to host US forces and sustain the alliance. Indeed, such public skepticism has already begun to emerge, led primarily by the younger generation.

The Rise of Millennials in Korean Politics

In South Korea, the growing influence of millennials in politics is hard to miss. These youngsters are bold and ambitious, revising the domestic political landscape not only with their words but also by their deeds. And their strident positions resonate throughout the entirety of Korean society. The recent decision by a group of college students to trespass onto the residence of the US Ambassador to Korea in protest of the Trump administration’s hard line on burden-sharing is an ideal example of their feisty tactics and penchant for attention seeking.[xvii]

Their political influence in politics is growing because Korean politicians, who are enthusiastically using social network services as a self-marketing channel, are increasingly cognizant of the need to be attentive to the voices of the younger generation.[xviii] Seeking to capture this support could be hugely valuable, and so politicians are increasingly inclined to cater to the preferences of these young voters. Indeed, with strong support from the youngest generation, the Moon administration has lowered the voting age from 19 to 18 through a revision to the constitution in December 2019.[xix]

The growing political power of millennials in South Korea presents the U.S. with a formidable challenge, as these youngsters do not have the same emotional attachment to the US-ROK alliance as their parents and grandparents.[xx] The older generations, with their memories of a time when the North maintained a clear material advantage over the South, have an emotional connection with US-ROK alliance. They view their American partners as having served as a critical stabilizing factor on the Korean peninsula over the past decades. The younger generation, by contrast, grew up in a rich and dominant South Korea and therefore lack a strong emotional attachment to the alliance. As a result, they have mostly come to see the alliance as merely a tool by which Washington controls Seoul. It is no surprise, then, that the student trespassers shouted, “[s]top interfering with our domestic affairs!” and “[w]e don’t need U.S. troops!” as they crossed into the American ambassador’s compound.[xxi]

Serving for the Strategic Interests

Among the public, there is a view that the US-ROK alliance and the military exercises it supports are the main sources of increased tensions on the Korean Peninsula. Even as the move to reduce the size and scope of the exercises has not changed Pyongyang’s hostile activities over the last year, the burden-sharing tensions continue to grow, especially after the Trump administration demanded a five-fold increase in South Korea’s financial support for US forces on the peninsula.[xxii] Against this backdrop, Trump’s decision to continue exercises at a reduced scale has undermined Washington’s ability to appeal to the values of alliance when engaging with the South Korean public, particularly its younger members. This does not mean that Washington should restore US-ROK exercises to their pre-Hanoi levels, necessarily. But for the US Asia-Pacific strategy to work, it requires the buy-in of South Korea. Consequently, the U.S. must care more about public opinion in its South Korean ally before the current negative trajectory becomes irreversible.


[i] Uri Friedman, “How to Choose Between the U.S. and China? It’s Not That Easy,” The Atlantic, July 26, 2019,

[ii] Aaron Mehta, “Pentagon shrinks key US-South Korean military exercise,” Military Times, November 21, 2018,

[iii] Bruce Klingner, “Enhance South Korean Military Capabilities Before OPCON Transfer,” The Heritage Foundation, December 2, 2019,

[iv] “Indo-Pacific Strategy Report,” The Department of Defense, June 1, 2019,

[v] Jaechun Kim, “South Korea’s Free and Open Indo-Pacific Dilemma,” The Diplomat, April 27, 2018, accessed March 3, 2020,

The Department of Defense, “Exercise Ulchi Freedom Guardian 2017,” August 18, 2017,

[vii] Sam LaGrone, “U.S. Conducting Dual Carrier-Ops Off Korean Peninsula Amidst Chinese Concern,” USNI News, May 31, 2017,

[viii] 이귀원, “美전폭기 한반도 전개비용은…美언론 “시간당 5천만~1억3천만원,” Yonhap News, June 20, 2018,

[ix] Matthew Fuhrmann and Todd S. Sechser, “Signaling Alliance Commitments: Hand-Tying and Sunk Costs in Extended Nuclear Deterrence,” American Journal of Political Science, Vol. 58, No. 4, October 2014, pp.919-935.

[x] Kyle Haynes, “Signaling Resolve or Capability? The Difference Matters on the Korean Peninsula,” War On the Rocks, May 10, 2017,

[xi] Lucas Tomlinson, “Pentagon shoots down reports of SEAL team Six training in South Korea,” Fox News, March 14, 2017,

[xii] Franz-Stefan Gady, “US, South Korea Kick Off Annual Military Drill Without US ‘Strategic Assets’,” The Diplomat, April 03, 2018,

[xiii] Richard L. Moreland and Robert B. Zajonc, “Exposure Effects in Person Perception: Familiarity, Similarity, and Attraction,” Journal of Experimental Social Psychology, Vol. 18, 1982, pp. 395-415.

[xiv] Bruce Bennett, “The Sixty Years of the Korea-U.S. Security Alliance: Past, Present, and Future,” International Journal of Korean Studies Vol. XVII, No. 2, pp.1-43, p.17

[xv] Questionnaire. Public Opinion and Foreign Policy in the United States, China, India, Australia, and South Korea. 2006.

[xvi] Joo, Hyo Sung, “South Korean Men and the Military: The Influence of Conscription on the Political Behavior of South Korean Males” (2015). CMC Senior Theses. Paper 1048. p.77

[xvii] Kim Bellware, “Seoul students scale wall outside U.S. ambassador’s residence to protest American troop presence in South Korea,” The Washington Post, October 19, 2019,

[xviii] Eunil Cho, “SNS Democracy in Korea,” The Diplomat, October 17, 2011,

[xix] Sung-jin Park, “High school voters emerge as new variable in April 15 general elections,” The Dong-A Ilbo,January 06, 2020,

[xx] Stuart Leavenworth, “South Korea’s millennials could determine fate of U.S. alliance,” The Seattle Times, August 17, 2017,

[xxi] Hyonhee Shin, “South Korean students climb into U.S. envoy’s residence in protest against troop presence,” October 18, 2019,

[xxii] Timothy W. Martin, “North Korea Fires Two Apparent Missiles in Its First Test This Year,” WSJ, March 2, 2020,

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.